Methods: Children were recruited from elective surgical lists and a non-bronchoscopic bronchoalveolar lavage (BAL) was performed after induction of anaesthesia. Exhaled nitric oxide (parts per billion) was measured by two techniques: tidal breathing and restricted breath.
Results: Median (interquartile range) exhaled nitric oxide measured by restricted breath was increased in asthmatics compared with normal children (24.3 (10.5–66.5) v 9.7 (6.5–16.5), difference between medians 14.6 (95% CI 5.1 to 29.9), p=0.001). In asthmatic children exhaled nitric oxide correlated significantly with percentage eosinophils (r=0.78, p<0.001 (tidal breathing) and r=0.78, p<0.001 (restricted breath)) and with eosinophilic cationic protein (r=0.53, p<0.01 restricted breath)), but not with other inflammatory cells in the BAL fluid. The area under the receiver operator characteristic curves for the prediction of the presence of eosinophilic airways inflammation by exhaled nitric oxide (tidal and restricted) was 0.80 and 0.87, respectively.
Conclusions: Exhaled nitric oxide correlates closely with percentage eosinophils in BAL fluid in asthmatic children and is therefore likely to be a useful non-invasive marker of airway inflammation.
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
Liam Heaney (Participant), Ian Cadden (Participant), Michael Shields (Participant), Madeleine Ennis (Participant), Bettina Schock (Participant), Vanessa Brown (Participant), Michael Ryan (Participant), Dennis Carson (Participant) & Timothy Warke (Participant)
Impact: Health Impact, Quality of Life Impact